require("dotenv").config();
const sql = require("mssql");

const isProduction = process.env.NODE_ENV === "production";

// Config SQL Server
const config = {
  user: process.env.SQL_USERNAME,
  password: process.env.SQL_PASSWORD,
  database: process.env.SQL_DATABASE,
  server: process.env.SQL_HOST,
  port: parseInt(process.env.SQL_PORT, 10),
  options: {
    encrypt: false, // true kalau Azure
    trustServerCertificate: true,
  },
};

// Buat pool global
const poolPromise = new sql.ConnectionPool(config)
  .connect()
  .then(pool => {
    console.log("✅ Koneksi SQL Server berhasil");
    return pool;
  })
  .catch(err => {
    console.error("❌ Gagal koneksi SQL Server:", err);
    process.exit(1);
  });

/**
 * Wrapper query (auto konversi $1 → @p1)
 */
async function query(text, params = []) {
  const pool = await poolPromise;
  const request = pool.request();

  params.forEach((param, i) => {
    request.input(`p${i + 1}`, param);
  });

  // Ubah $1, $2 jadi @p1, @p2
  const sqlText = text.replace(/\$(\d+)/g, (_, num) => `@p${num}`);

  console.log(sqlText, params);
  return request.query(sqlText);
}

/**
 * Build filter query
 */
function buildFilterQuery(filterQuery = [], fixedParams = []) {
  let whereConditions = [];
  let queryParams = [...fixedParams];

  filterQuery.forEach((f) => {
    if (f.param === undefined || f.param === null || f.param === "") return;

    switch (f.type) {
      case "string":
        queryParams.push(`%${f.param}%`);
        whereConditions.push(`${f.column} LIKE $${queryParams.length} COLLATE SQL_Latin1_General_CP1_CI_AS`);
        break;

      case "number":
        queryParams.push(f.param);
        whereConditions.push(`${f.column} = $${queryParams.length}`);
        break;

      case "boolean":
        queryParams.push(f.param ? 1 : 0);
        whereConditions.push(`${f.column} = $${queryParams.length}`);
        break;
    }
  });

  return { whereConditions, queryParams };
}

/**
 * Build OR ILIKE (SQL Server pakai LIKE + COLLATE)
 */
function buildStringOrIlike(columnParam, criteria, fixedParams = []) {
  if (!criteria) return { whereClause: "", whereParam: fixedParams };

  let orStringConditions = [];
  let queryParams = [...fixedParams];

  columnParam.forEach((column) => {
    if (!column) return;
    queryParams.push(`%${criteria}%`);
    orStringConditions.push(`${column} LIKE $${queryParams.length} COLLATE SQL_Latin1_General_CP1_CI_AS`);
  });

  const whereClause = orStringConditions.length
    ? `AND (${orStringConditions.join(" OR ")})`
    : "";

  return { whereOrConditions: whereClause, whereParam: queryParams };
}

/**
 * Build dynamic UPDATE
 */
function buildDynamicUpdate(table, data, where) {
  const setParts = [];
  const values = [];
  let index = 1;

  for (const [key, value] of Object.entries(data)) {
    if (value !== undefined && value !== null) {
      setParts.push(`${key} = $${index++}`);
      values.push(value);
    }
  }

  if (setParts.length === 0) {
    throw new Error("Tidak ada kolom untuk diupdate");
  }

  // updated_at otomatis pakai GETDATE()
  setParts.push(`updated_at = GETDATE()`);

  const whereParts = [];
  for (const [key, value] of Object.entries(where)) {
    whereParts.push(`${key} = $${index++}`);
    values.push(value);
  }

  const query = `
    UPDATE ${table}
    SET ${setParts.join(", ")}
    WHERE ${whereParts.join(" AND ")}
  `;

  return { query, values };
}

/**
 * Build dynamic INSERT
 */
function buildDynamicInsert(table, data) {
  const columns = [];
  const placeholders = [];
  const values = [];
  let index = 1;

  for (const [key, value] of Object.entries(data)) {
    if (value !== undefined && value !== null) {
      columns.push(key);
      placeholders.push(`$${index++}`);
      values.push(value);
    }
  }

  if (columns.length === 0) {
    throw new Error("Tidak ada kolom untuk diinsert");
  }

  // created_at & updated_at otomatis
  columns.push("created_at", "updated_at");
  placeholders.push("GETDATE()", "GETDATE()");

  const query = `
    INSERT INTO ${table} (${columns.join(", ")})
    VALUES (${placeholders.join(", ")});
    SELECT SCOPE_IDENTITY() as inserted_id;
  `;

  return { query, values };
}

/**
 * Generate kode otomatis
 */
async function generateKode(prefix, tableName, columnName) {
  const pool = await poolPromise;
  const result = await pool.request()
    .input("prefix", sql.VarChar, prefix + "%")
    .query(`
      SELECT TOP 1 ${columnName} as kode
      FROM ${tableName}
      WHERE ${columnName} LIKE @prefix
      ORDER BY ${columnName} DESC
    `);

  let nextNumber = 1;
  if (result.recordset.length > 0) {
    const lastKode = result.recordset[0].kode;
    const lastNumber = parseInt(lastKode.replace(prefix, ""), 10);
    nextNumber = lastNumber + 1;
  }

  return prefix + String(nextNumber).padStart(3, "0");
}

module.exports = {
  query,
  buildFilterQuery,
  buildStringOrIlike,
  buildDynamicInsert,
  buildDynamicUpdate,
  generateKode,
};